1. Field of the Invention
The present invention generally relates to a LNB, in particular, to a LNB having indication function.
2. Description of Prior Art
LNB (Low Noise Block Down Converter, abbreviated and referred as LNB in the following) is a satellite feed used for lowering frequency and amplifying satellite signals. LNB is used for lowering the frequency of satellite signals from 3.4˜4.2 GHz (C band) or 0.7˜12.75 GHz (Ku band) to intermediate frequency required by satellite receiver (950 MHz˜2050 MHz, the required intermediate frequency range is subject to the types of LNB).
FIG. 1 is a schematic diagram illustrating a satellite receiver receiving satellite signals. Typically, a satellite 10 is distanced from the earth more than 30,000 km. Accordingly, satellite signals S1 of the satellite 10 is weakened upon arriving a dish antenna 20 and a LNB 30 then is used for amplifying the received satellite signals. A coaxial cable 50 is connected between the LNB 30 and a satellite receiver 60. Due to that the signal loss increases as the transmitting frequency of coaxial cable increases, the LNB 30 converts the frequency of the satellite signals S1 from high frequency to intermediate frequency via local oscillating circuit (not shown in the diagram) to facilitate the signal transmission of the coaxial cable 50 and modulation decoding on the satellite receiver 60 in order to display the sound and image carried by the satellite signals on a television set 70.
Traditionally, dish antennas are adjusted in a manner that a user 40A standing outdoors manually adjusts the position and angle of a dish antenna 20 whereas the other user 40B indoor stands in front of the satellite receiver 60 and the television set 70. As the outdoor user 40A adjusting the position and the angle of the dish antenna 20 for better reception of the satellite signals S1, the indoor user 40B talks to the outdoor user 40A directly or via a walkie talkie to inform the outdoor user 40A the display quality of satellite signals S1 on the television set 70, which can be inconvenient under many circumstances.
In order to address the above mentioned inconveniences, new products are developed yet with disadvantages such as the solution is not able to recognize the name of the satellite, the solution is expensive, the solution requires external device and steps to remove the external device upon adjustment is completed etc. . . .